3-DIMENSIONAL ULTRASOUND ASSESSMENT OF FETAL LIVER VOLUME IN NORMAL-PREGNANCY - A COMPARISON OF REPRODUCIBILITY WITH 2-DIMENSIONAL ULTRASOUND AND A SEARCH FOR A VOLUME CONSTANT

The purposes of this study are to compare the reproducibility of two-d imensional ultrasound (2DUS) and three-dimensional ultrasound (3DUS) i n the assessment of fetal liver volume (LV), and to test whether the f etal LV assessed by the traditional method with 2DUS is equal to that with 3DUS in normal pregnancy. If significantly different, we then try to calculate a new constant of fetal LV for the traditional equation from the LV values obtained with 3DUS. In total, 30 normal singleton f etuses with gestational ages ranging from 20 to 30 weeks were included for the reproducibility test and 55 cases ranging from 20 to 31 weeks gestation were enrolled for finding a new volume constant of LV. The results showed that 3DUS is superior to 2DUS in the reproducibility te st of fetal LV assessment. Moreover, the LV assessed with the traditio nal 2DUS method (identified as LV_42) was significantly smaller than t hat measured with 3DUS (P < 0.001). If the traditional 2DUS equation i s to be used, the multiplying factor in the equation for the calculati on of LV should be modified to 0.55 (SE = 0.017, N = 55). With the new volume constant, the new derived LV with 2DUS (identified as LV_55) w as not different from that with 3DUS (identified as LV_3D). In conclus ion, we recommend that 3DUS, instead of 2DUS, should be used for reach ing an accurate assessment of fetal LV. Otherwise, applying our new vo lume constant may be of help in detecting abnormal fetal liver growth when only 2DUS is available. (C) 1997 World Federation for Ultrasound in Medicine & Biology.